1. Field of the Invention
The present invention refers to improvements in machines for bevelling lenses, of the type comprising a fixed base and a hinged moving carriage with movement of the carriage towards the diverse working areas of a plurality of grinding wheels for reducing and bevelling the lenses, with self centering of the latter and comprising a tracing follower engaged by a spring loaded template, allowing for automatic operation from the time the lens is positioned, with capability of admitting any type, shape or grade of lens, apart from providing a more rational reducing and bevelling action than the machines used up to date. It also allows unskilled labour to be used.
2. Summary of the Invention
The above improvements are characterised in that the upper moving carriage carrying the actuating mechanisms is driven according to a tracing means which follows the profile of a template corresponding to the lens to be bevelled. The bevelling is effected through the successive action of the reducing wheel which provides the lens with a suitable peripheral design and by the bevelling wheel which provides the lens with the appropriate bevel. These grinding wheels are driven by respective motors and are housed in a lower fixed base of the machine. The lens to be bevelled is mounted on a shaft having a locking means for axial holding of the lens and which is driven through transmission means from an intermediate shaft associated in turn with a drive shaft, said intermediate shaft also driving a shaft carrying a double cam controlling the lateral movements and angular elevation of said moving carriage, through respective mechanisms, said carriage being guided by the tracing means which may be programmed according to different types and magnitudes of lenses by way of control elements which are adjusted in accordance with tables established for the diverse variables of the lenses.
The lens reducing process is effected when required by a quick action means, to shorten the process time, which in the areas where the lens is to be ground away to a greater depth, produces a forward and reverse reciprocating rotational movement of the lens relative to the reducing wheel.
The regulation of the difference of material to be removed from the lens between the reducing and the bevelling wheels is effected by a means which adjusts in each case the time the lens passes from one wheel to the other.